This peptide is histone H4 (1-25) with acetylation at Lys16 and monomethylation at Lys20, followed by a C-terminal GSGS linker and a biotinylated lysine. Lys16 is generally the first site of acetylation on histone H4. Monomethylation at Lys20 of H4 is catalyzed by PR-Set7 and concentrated in the nuclear periphery and heterochromatin of the inactive female X chromosome in vivo. Monomethylation of histone H4 at Lys20 is associated with transcriptional silent chromatin in higher eukaryotes. These two histone modifications are typically inversely correlated during the cell cycle. Provided at >95% peptide purity, this peptide was dissolved in distilled water at 1 mg/ml and re-lyophilized to powder form.